Mid-Atlantic Invaders Tool

alpine knapweed, Tyrol knapweed

Centaurea nigrescens

Willd

Taxon, Habit: Plant, Forb

Habitat: Terrestrial

U.S. Nativity: Introduced

Species Synonym(s): None

Common Name(s): Tyrol knapweed, short-fringed knapweed, vochin knapweed

Family: Asteraceae (Aster Family)

Family Synonym(s): None

Native Range (GRIN):

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Plant

Joseph M. DiTomaso, University of California - Davis

Flower

Joseph M. DiTomaso, University of California - Davis

Plant

Eric Coombs, Oregon Department of Agriculture

Plant

Eric Coombs, Oregon Department of Agriculture

Description

Appearance
Centaurea nigrescens is a perennial herb with erect, branched, glabrous or somewhat long-hairy stems that grows 1.3-3.2 ft. (0.4-1.0 m) tall.
Foliage
Stems are erect or ascending, openly branched distally, villous to scabrous with septate hairs and loosely tomentose. Leaves are basal and proximal cauline, petiolate, blades oblanceolate or elliptic, 2-10 in. (5-25 cm) long, margins entire or shallowly dentate to irregularly pinnately lobed; distal cauline sessile, not decurrent, blades linear to lanceolate, gradually smaller, entire or dentate.
Flowers
Flowers are radiant or discoid, in few-headed corymbiform arrays, borne on leafy-bracted peduncles. The involucres are 0.6-0.7 in. (15-18 mm), subcylindric to ovoid or campanulate, usually longer than wide, even when pressed. Flowering summer-fall (Jun-Oct).
Fruit
Fruit are gray to light brown, 0.09-0.11 in. (2.5-3 mm) long, and finely hairy. The seeds are small, 0.02-0.04 in. (0.5-1 mm) long, and darkly colored.
Ecological Threat
Centaurea nigrescens can be found in disturbed areas including along roadsides, fields, pastures, and waste areas. It is native to Europe.

Uses

Landscape Ornamental Use (GRIN): No

All Uses (GRIN):

Distribution Map (EDDMapS)

Wetland Indicator

Summary: alpine knapweed, Tyrol knapweed (Centaurea nigrescens) is a Terrestrial species.

Atlantic and Gulf Coastal Plain (AGCP):

Mid-Atlantic Coastal Plain regions

No Data

Eastern Mountains and Piedmont (EMP):

Mid-Atlantic Piedmont and Mountain regions

No Data

Northcentral and Northeast (NCNE):

Northern parts of PA and NJ (and beyond)

No Data


Legend (data from U.S. Army Corps of Engineers)

OBL (Obligate wetland): Almost always occurs in wetlands (estimated probability > 99%) under natural conditions

FACW (Facultative wetland): Usually occurs in wetlands (estimated probability 67% - 99%), but occasionally found in non-wetlands

FAC (Facultative): Equally likely to occur in wetlands (estimated probability 34% - 66%) or non-wetlands

FACU (Facultative upland): Usually occur in non-wetlands (estimated probability 67% - 99%), but occasionally found in wetlands (estimated probability 1% - 33%)

UPL (Obligate upland): Occur almost always (estimated probability > 99%) in non-wetlands under natural conditions

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Subclass: Asteridae
Order: Asterales
Family: Asteraceae
Genus: Centaurea
Subject: Centaurea nigrescens Willd

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